A room device comprising two or more connectors (2a, 2b, 15) for providing building power to the room device (1); a device controller (3a) configured to operate a heating, ventilation and/or air-conditioning system (4); a device memory (3b) in operative communication with the device controller (3a); wherein the device memory (3b) and the device controller (3a) require building power for standard operation; a transponder controller (5a) and an antenna (5c); a transponder memory (5b) being powerable by the transponder controller (5a); a device firmware stored in the device memory (3b), the device firmware including instructions causing the device controller (3a) upon providing building power to the room device (1) to: connect to the transponder controller (5a) such that the device controller (3a) is in operative communication with the transponder controller (5a); transfer the initial configuration data stored in the transponder memory (5b) to the device memory (3b).